docs: def variable(
              self,
              name=None,
              function=None,
              decl_type=None,
              header_dir=None,
              header_file=None,
              recursive=None):
          """returns reference to variable declaration, that is matched defined
          criteria"""
  
          return (
              self._find_single(
                  self._impl_matchers[
                      scopedef_t.variable],
                  name=name,
                  function=function,
                  decl_type=decl_type,
                  header_dir=header_dir,
                  header_file=header_file,
                  recursive=recursive)
          )